Millions of dollars worth of measures from the May budget remain stuck in the Senate, while revenues have been hit by a slump in the iron ore price, which extended its fall to a five-year low this week.

Mr Shorten said it is not the first time the government has had to consider a "reboot" of the budget.

"It's not the barnacles on the budget - on this unfair budget - which are impeding it, it's that this unfair budget has sunk without a trace," Mr Shorten told reporters in Melbourne.

He thinks Mr Abbott should instead start his budget again, saying it is not a question of rebooting it.